During the night we can see how the stars change position gradually following a sort of pre-established path, in fact the stars we see in winter are not the same that we see the summer and the stars we see in the morning will not be in the same position of the evening before. All this is due to the rotation of the Earth that gives life to the apparent motion of the stars. The only star to be still (even if in reality there is a displacement of about 1 degree around the center) is the polar star, while all the others give the impression of rotating around it.
A single shot for the mountains and a lots of shot for the start rail (2/3 hour).
Nikon D5100 - 18-105mm - Manfrotto tripod
looks so cool , nice job getting the circle dead center